The present paper describes a project that emphasized the use of case-writing by teachers engaged in an educational innovation. The aims of the paper are threefold: to provide a somewhat detailed description of the case-writing process, to explicate the varied functions of cases and case-writing by teachers, and to discuss an important feature of cases and case-writing that might explain their power. The main argument is that cases could be used to achieve three purposes: to promote, to describe, and to explain teacher and educational change. The description of the case-writing process and an analysis of the cases themselves reveal their great potential in achieving these three aims. Additionally, it is argued that cases and case-writing facilitate border-crossing, or the integration of theory/practice, research/narration, and cognition/emotion, an integration necessary for authentic professional activities. This seminal feature of cases and case-writing also accounts for their potential in achieving the previously mentioned functions.